Garage door operator



March 18, 1952 U -11s GARAGE DOOR OPERATOR 2 SHEETS SHEET 2 Filed Dec. 7, 1946 IN V EN TOR.

Guy 4. 602775 Hrraexvs 75 Patented Mar. 18, 1952 GARAGE DOOR OPERATOR Guy A. Curtis, Cleveland Heights, Ohio, assignor to United States Motors Corporation, Oshkosh, Wis., a corporation of Wisconsin Application December 7, 1946, Serial No. 714,826

This invention relates to improvements in garage door operators. More particularly it relates to electrical means for automatically controlling motor means for opening and closing garage doors through the action of an electromagnet with reversible polarity.

In accordance with the present invention the driver of the automobile may operate a selector switch momentarily to complete a direct current circuit in either direction through the electromagnet While the latter passes over a magnetically responsive switch buried in the driveway, whereby a momentary electrical impulse is imparted to one or the other of two electric control circuits, each of which functions to cause actuation of the door operating motor means in one direction or the other.

One of the objects of the invention is the provision of means responsive to magnetic action for automatically operating a door actuating motor means selectively in either direction.

Another object of the invention is the provision of an electrical system responsive to a momentary electrical impulse in one or the other of two control circuits for operating door actuating motor means in either door opening or door closing direction.

Still another object is the provision of a simple, troubleproof switch assembly adapted to be buried in a pavement, responsive to magnetic lines of force for closing either one of two control circuits.

Other objects and features of novelty will appear as I proceed with the description of that embodiment of the invention which, for the purposes of the present application, I have illustrated in the accompanying drawings, in which Fig. 1 is an elevational view illustrating the application of the invention.

Fig. 2 is a vertical sectional view of a magnetically responsive switch adapted to be buried in the pavement of a driveway, the view being taken substantially on the line 22 of Fig. 3.

Fig. 3 is a plan view partially in section on the line 33 of Fig. 2.

Fig. 4 is a vertical sectional view of the switch assembly taken substantially on the line 4-4 of Fig. 3, and

Fig. 5 is a wiring diagram.

In Fig. 1, I0 represents the pavement of a driveway leading to the doorway ll of a garage which may be closed by a door of any desired character, that illustrated herein being a, door of two parts l2 and I3 joined in the middle by a horizontal hinge I4. The upper section I2 is 2 Claims. (Cl. 318267) hinged at [5 to the rail above the doorway. At the bottom of the door are side rollers, not shown, running in vertical tracks, also not shown, in the stiles of the door frame. A cable [6 secured to the upper door section I2 extends up to and is wound around a drum ll, shown diagrammatically as directly connected to the shaft of a reversible electric motor l8, although of course it is to be understood that in practice gearing would be interposed between the motor and the drum in order to decrease speed and increase torque.

In the pavement I0 I bury one or more switch assemblies l9 encased in non-magnetic housings from which lead conduits 2| for the protection of the necessary electrical conductors. Where a single housing is employed it is placed in line with the center of the doorway l I. Where a pair of such housings are employed they may be spaced a matter of a foot or so on either side of the said center line. The housing itself is made cup-shape and its upper end is closed by a cover plate 22 which may be soldered to the rim of the cup.

Cover 22 carries a stirrup 23 formed of strip metal in the base of which there are mounted two hollow supports 24 which receive loosely pins 25 of hard steel that are preferably pointed at their upper ends. These pins extend into conical cavities 26 formed in the under side of a pivot bar 21 of non-magnetic material. By reason of this construction the points of the pins readily find the apices of the cavities 26 and an excellent pivotal bearing results regardless of possible inaccuracies in machining and assembling the parts. Near its ends the bar 21 is drilled to receive with a snug fit two permanent bar magnets 28, the opposite ends of which project equal distances from the bar Zl, so that the parts 21 and 28 together are balanced on the pins 25, the bar magnets 28 normally standing in a substantially horizontal position.

Between the cavities 28 the pivot bar 21 carries a pair of sheet metal loops 30 and 3| which are fixed to the bar and disposed at the same angle with the vertical but on opposite sides of the plane through the pins 25. In these loops are mounted mercury tube switches 32 and 33 which face in opposite directions. In the normal condition of the switch assembly, illustrated in the drawings, the mercury globules in the switch tubes are inoperative. In the then upper ends 3 and 35 of the two tubes there are pairs of terminals adapted to be joined by the mercury globules in the tubes. Flexible conductors 36 and 3! leading from the terminal ends of the two switches are joined to a conductor 38, while flexible conductors 39 and 40 are joined with conductors 4| and 42. The three conductors 38, 4| and 42 which provide parts of two low voltage control circuits are fixed to the lower surface of stirrup 23 by a clip 43 or other similar means, so that movements of the switch assembly upon its pivots produce substantially no relative movement of the conductors 35, 31, 39 and 40. Inasmuch as the contacts in the mercury tube switch are protected against humidity and oxidation, and inasmuch as the only movement in the assembly is the tilting of the pivot bar 21 and supported parts upon the supporting pins 25, the switch assembly, although buried in the ground, has an extended life and requires substantially no servicing.

Suspended from the automobile by any suitable means is a vertically disposed electromagnet 50. From the opposite ends of the coil of this magnet conductors and 52 lead to a double pole. double throw, momentary contact switch 53 mounted on the instrument board of the automobile. The poles of this switch are also connected by conductors 54 and 55 with the positive and negative terminals of the storage battery 56 of the automobile. Switch 53 is biased toward off position. It may be swung from this position by the operator to direct current.

through the electromagnet in either direction, as will be obvious from an inspection of the diagram of Fig. 5. When the automobile is in the right position magnet to is close enough to the buried switch assembly to cause the bar magnet or magnets 28 to tilt from the intermediate position illustrated to one in which the north pole or the south pole of the bar magnet is inclined upwardly. When this occurs the switch tubes 32 and 33 are tilted correspondingly and the terminals at one or the other of the two ends 34 and 35 of the tubes are connected by the mercury globules in that tube.

5'! and 58 are line conductors from which wires 59 and 69 lead to the primary coil SI of a stepdown transformer. The secondary coil 6 of this transformer supplies low tension current to the conductors of the control circuits. These circuits includ the coils of two relays 62 and 63. Current for relay 62 flows from the secondary coil 6|" of the transformer through conductors 64 and 65 to the coil and out through conductor 42 to the end 35 of tube 33, and when that end is depressed back through conductor 38 to the transformer. Similarly, current for the coil of relay E3 flows from the transformer through conductors 64 and 96 to the coil, through conductors 4| and 39 to the end 34 of mercury tube 32, and when that end is depressed back through conductors 39 and 38 to the transformer. 61 and 58 (Fig. 5) represent limit switches which are biased toward closed position. These switches are so disposed that when the door l2, I3 reaches fully open position it opens switch 51, and when it reaches fully closed position it opens switch 68. Relays 62 and 63 have armatures 69 and 19. H and 12 are holding relays having two armatures 13, 14 and 15, I6 respectively.

Assuming that the door is closed and that relay 62 is energized because lines of magnetic force of the proper polarity tilt the switch assembly IS in the proper direction, then armature 69 will be raised and will complete a circuit from the transformer through relay II by way or conductors 6.4 and I7. closed switch 61.

conductor 18, the coil of relay H, conductor 19, armature 69 and conductors 80, 8| and 82 back to the transformer. When this occurs relay H is locked-in independently of relay 52.' Current for this purpose flows from the transformer through conductors B4 and TI, closed switch 61, conductor 18, the coil of relay 1|,raised armature 13 and conductors 83, 8| and 82 back to the transformer.

At the same time armature |4 closes a high voltage circuit from line wire 58 through conductors 84 and 85, armature 14 and conductor 86 to motor l8 and from the motor to line wire 51, causing the motor to rotate in the direction for winding cable IS on drum I! to open the door. As soon as the door reaches fully open position it opens limit switch 61, thereby breaking the circuit through the coil of relay H and permitting armature 14 to swing up, breaking the motor circuit.

At the start of the door opening movement limit switch 68 was permitted to close. It remains closed until the door again assumes fully closed position. After the door is opened the automobile will be driven into the garage. The operator may close the door by manipulating a manual switch 99 which may be located in any convenient position, as for example inside the house on the same premises. This switch may also be a momentary contact switch and may be similar to switch 53, but as herein shown is a two pushbutton type of switch. By operating this switch to connect conductors 9| and 92 the operator may cause current to flow from coil 6| of the transformer through conductors 64 and 66 to the coil of relay 63, through conductors 4| and 9| to switch and through conductors 92, 38 and 82 back to the transformer. When this occurs armature 1|] is raised and current flows from the transformer through conductors 64 and 94, the then closed limit switch 68, conductor 95, the coil of relay 12, conductor 95, armature l9 and conductors 91, 8| and 82, back to the transformer. Armature 15 is thereby raised and relay 12 is locked-in by current flowing from the transformer through conductors 64 and 94, limit switch 68, conductor 95, the coil of relay l2, raised armature 15 and conductors 98, 8| and 82 back to the transformer. Armature 15 is of course swung down by the energization of relay T2 and a circuit through motor i8 is set up for rotation of the motor in a direction opposite to that first described, by way of line wire 58, conductor 99, armature 16 and conductor I09 to the motor and back through line wire 51.

As soon as the door starts away from open position switch 51 closes, and when the door reaches closed position switch 68 opens. Now with the automobile in the garage, if the operator wishes to open the door he presses on the lower pushbutton of the switch 99 to connect conductors 42 and 38 through conductors WI and 92, the control circuits operating in the same manner as though the conductors 42 and 38 had been connected by the operation of the switch assembly l9. When the door has been opened the automobile may be backed out of the garage and as it passes over the switch assembly t9 the operator may move switch 53 to produce current flow through conductors 52 and 5| in a, direction opposite to that first described. The bar magnets 28 will then be tilted in the opposite direction, that is with the south poles uppermost, and a controlcirsui w ther by be set up though conductors 4| and 38, energizing relays 63 and 12, causing the door to close.

It will be appreciated that although I have shown in the drawings a single reversible motor [8 with means for causing it to operate in either direction depending upon which of the two control circuits is energized, separate motors for opening and closing the doors could be employed and controlled by substantially the same control circuits. Other variations from the described structure may be employed. Accordingly, I desire it to be understood that the scope of the invention is to be regarded as defined exclusively by the appended claims rather than by the fore-- going description or the accompanying illustrations.

Having thus described my invention, I claim:

1. In motor driven means for opening and closing a garage door, two electrical control circuits, a balanced switch assembly adapted to be buried in the pavement in front of said door, said assembly comprising a pivotally mounted bar magnet and switch means secured to said magnet responsive to movement of the latter about its pivot in one direction or the other for selectively closing either one of said circuits, an electromagnet adapted to be suspended from an automobile and means for reversing the current through said magnet for tilting said bar magnet in one direction or the other, and means responsive to current in one or the other of said circuits for energizing said motor driven means for opening or closing said door.

2. In motor driven means for opening and closing a garage door, two electrical control circuits, a balanced switch assembly adapted to be buried in the pavement in front of said door, said assembly comprising a pivotally mounted bar magnet and a pair of oppositely disposed mercury switches secured to said magnet, each of said control circuits being adapted to be closed by one of said switches as the bar magnet tilts in one direction or the other, an electromagnetadapted to be suspended from an automobile and means for reversing the current through said magnet for tilting said bar magnet in one direction or the other, and means responsive to current in one or the other of said circuits for energiing said motor driven means for opening or closing said door.

GUY A. CURTIS.

REFERENCES CITED Ihe following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 898,766 Mott Sept. 15, 1908 1,935,017 Capre Nov. 14, 1933 1,951,409 Havenner et al. Mar. 6, 1934 2,118,930 Lilja May 31, 1933 2,186,311 Weathers Jan. 9, 1940 2,240,891 Marchant May 6, 1941 2,412,871 Clark Dec. 17, 1945 2,435,440 Graham Feb. 3, 1948 

